Solid state light sources may be utilized to provide white light (e.g., perceived as being white or near-white), and have been investigated as potential replacements for white incandescent lamps. Light perceived as white or near-white may be generated by a combination of red, green, and blue (“RGB”) emitters, or, alternatively, by combined emissions of a blue light emitting diode (“LED”) and a yellow phosphor. In the latter case, a portion of the blue LED emissions pass through the phosphor, while another portion of the blue LED emissions is “downconverted” to yellow; the combination of blue and yellow light provide a white light. Another approach for producing white light is to stimulate phosphors or dyes of multiple colors with a violet or ultraviolet LED source. A solid state lighting device may include, for example, at least one organic or inorganic light emitting diode and/or laser.
Many modern lighting applications require high power solid state emitters to provide a desired level of brightness. High power solid state emitters can draw large currents, thereby generating significant amounts of heat that must be dissipated. Many solid state lighting systems utilize heatsinks in thermal communication with the heat-generating solid state light sources. For heatsinks of substantial size and/or subject to exposure to a surrounding environment, aluminum is commonly employed as a heatsink material, owing to its reasonable cost, corrosion resistance, and relative ease of fabrication. Aluminum heatsinks for solid state lighting devices are routinely formed in various shapes by casting, extrusion, and/or machining techniques. Leadframe-based solid state emitter packages also utilize chip-scale heatsinks, with such heatsinks and/or leadframes being fabricated by techniques including stamping (e.g., U.S. Pat. No. 7,224,047 to Carberry, et al.); with such chip-scale heatsinks typically being arranged along a single non-emitting (e.g., lower) package surface to promote thermal conduction to a surface on which the package is mounted. Such chip-scale heatsinks are generally used as intermediate heat spreaders to conduct heat to other device-scale heat dissipation structures, such as cast or machined heatsinks.
Despite the existence of various solid state lighting devices with heatsinks, improvements in heatsinks are still required, for example, to serve the following purposes: (1) to provide enhanced thermal performance; (2) to reduce material requirements; (3) to simplify manufacture of high-power and self-ballasted) lighting devices, and/or (4) to enable production of various desirable shapes to accommodate solid state lighting devices adapted to different end use applications.